A magnitude 6.4 earthquake has struck the tourist island of Lombok in Indonesia, killing 14 people, authorities have said.

The quake hit early in the morning, while many people were sleeping. Around 40 people were also injured.

The quake was centred 50km (31 miles) north-east of the city of Mataram on the northern part of Lombok island, the US Geological Survey said.

Around 43 quakes were recorded after the initial 6.4 magnitude tremor, with the largest aftershock recorded at a 5.7 magnitude, said the disaster mitigation agency.

The quake was also felt on the neighbouring island of Bali.

A magnitude 6.4 earthquake is considered strong and is capable of causing severe damage.

Indonesia is an archipelago of thousands of islands, which sit on the Pacific Ring of Fire, a seismic activity hotspot.

The region is often hit by quakes, but many are harmless. However, it is alert to tremors that could trigger tsunamis. The worst on record was in 2004 after a magnitude 9.3 undersea earthquake triggered a tsunami in western Indonesia, which killed 222,000 people in the area.